A magnetic resonance imaging apparatus measures a density distribution of an atomic nucleus spin (hereinafter merely called “spin”), a relaxation time distribution, etc, at a desired inspection portion in a subject by utilizing the NMR phenomenon and displays an image of an arbitrary section of the subject from the measurement data. Particularly, the magnetic resonance imaging apparatus has an imaging function called “contrast enhanced MR angiography” (hereinafter abbreviated as “CE-MRA”) that depicts the blood vessel with high signals by using a contrast agent.
When a contrast agent is injected from an elbow vein, for example, the contrast agent ejected through the heart first enhances the signals of the artery system and then the vein system through the capillary. In clinical diagnosis of diseases, depiction of not only the artery system but also the vein system is necessary in some cases, and imaging by CE-MRA is preferably carried out in some cases continuously throughout a plurality of time phases. Such an imaging method is called “dynamic MRA measurement (hereinafter abbreviated as “dynamic measurement”).
In this dynamic measurement, time resolution is of importance to improve diagnostic accuracy of the diseases but it has a trade-off relation with spatial resolution or a signal to noise ratio (S/N) determined by a phase encode number and a slice encode number. Therefore, a method that divides the measurement space (hereinafter abbreviated as “k space”) into a plurality of areas, shares measurement data of the same area among a plurality of time phases and substantially shortens the imaging time per measurement is disclosed in JP-A-2002-177240.
In dynamic measurement, however, the number of measurement data (number of time phases) becomes great. In the case of three-dimensional imaging, in particular, the operation of extracting only three-dimensional data constituting an artery phase (time phase in which the artery is mainly depicted) necessary for the diagnosis from among a large number of measurement data is complicated and there remains the problem that generating and review (diagnosis) of the two-dimensional image of the artery phase cannot be made immediately after imaging.
JP-A-2002-177240 described above does not disclose a method for extracting the measurement data of a desired artery phase from among a plurality of time series data measured.